In many cases, the optical systems used in laser beam scanning copying instruments, imaging instruments, such as printers and the like, and projectors, such as liquid crystal projectors, have mirrors in order to re-direct the optical path of light beams. Some such mirrors are able to adjust their tilt angles to reflect light at different angles, and such adjustment mechanisms are disclosed in Japanese Laid-Open Patent Application No. H11-281876. In this publication, the lower, fixed end of the minor sits on a support and is pressed by a lower leaf spring against a mid-support which supports the back of the mirror near its lower edge. And at the same time, the upper edge of the mirror is pressed by two upper leaf springs against respective mirror adjustment brackets which support the back of the mirror near the mirror""s left and right edges. By adjustment of the mirror adjustment brackets, the mirror can be tilted left and right as well as tilted up and down, thus enabling the mirror to be adjusted in two directions by moving the mirror adjustment brackets.
In the adjustment mechanism disclosed in the above publication, one lower leaf spring near the fixed lower edge of the mirror and two upper leaf springs near the adjustable upper edge of the mirror are required as the flexible components. Furthermore, in addition to the above parts, a mirror adjustment bracket and fixing screws are required, which makes the entire mechanism less economical, due to the number of parts required. In addition, in order to adjust the tilt angle of the mirror, the fixing screws need to be loosened and then tightened in order to move the mirror adjustment bracket, which complicates the operation for the adjustment. Furthermore, the tilt angle adjustment of the mirror needs to be accomplished after the mirror and the other support parts are directly attached to the steel case, which is not a particularly efficient production method.
The present invention relates to a mirror support structure that enables simpler adjusting of the mirror orientation in an optical system. The mirror support structure of the present invention also has fewer parts than prior art mirror support structures in order to reduce production costs, and its design enables mirror adjustment to be accomplished at the same time that the parts are assembled, thereby improving integrated production efficiency.